Messages in this thread | | | Date | Thu, 25 Mar 2010 22:36:42 +0100 | From | Pavel Machek <> | Subject | Re: [RFC 09/15] PM / Hibernate: user, implement user_ops writer |
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On Wed 2010-03-24 22:40:56, Jiri Slaby wrote: > On 03/24/2010 09:42 PM, Pavel Machek wrote: > >> + if (test_bit(TODO_CLOSED, to_do_flags)) > >> + return -EIO; > >> + > >> + to_do_buf = buf; > >> + wmb(); > >> + set_bit(TODO_WORK, to_do_flags); > >> + wake_up_interruptible(&to_do_wait); > > > > Uhuh, open-coded barriers... these need to be commented, and I guess > > you just should not play this kind of trickery. > > It's just to ensure the to_do_buf store is not reordered with the > set_bit. I wanted to avoid locks as too heavy tools here.
Locks are the only sane choice here. Open coding them is not an option. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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